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Showing posts with label linux. Show all posts
Showing posts with label linux. Show all posts

Tuesday, 12 September 2017

disk-benchmark A mutlipurpose benchmark program that can simulate your application's I/O performance

disk-benchmark tool - get it here!

Sometimes we need to have a prior estimation of I/O performance of a program we plan to develop or we currently posses.
This may be triggered by a number of reasons:
  • Order specific Disk hardware in advance
  • Plan to rent cloud based volume from a cloud provider
  • Estimate the total performance of your application in order to establish operational scenarios and calculate KPIs.
  • Check the cloud providers SLA compliance.
In the past I dealt with all those challenges using standard Linux methods for benchamarking a volume like the classic one:


dd if=/dev/zero of=/root/testfile bs=1G count=1 oflag=direct

Or other similar methods or tools like iostat.

The problem with all those methods, is that you can have an idea of how your disk performs in general, but not according to a given scenario, for example:
  • 20 concurrent users each of them reads and writes of a random file of size between 20k and 1 MB with a pause of 2 seconds for 5 mins.
  • 10 concurrent users each of them reads/ writes a file of 60kb with a pause of 2 seconds after read repeatedly for 100 times. 


Unless you go to very sophisticated tools like JMeter,  you don't really have something very handy. On the other hand, sophisticated tools most of the times, have a significant learning curve but of course in most cases, you want something to use it in the next 5 mins with very simple options just like the above scenarios. To amend this situation, last year, I developed a small C program that can be used to do the job, the disk-benchmark program available on Illumine IT Consulting GitHub URL:

https://github.com/illumine/disk-benchmark

This is a benchmark program to test Hard Drives, SSD Drives, HBAs, RAID Adapters & Storage Controllers. This is a really simple C program that you can compile using the standard GNU/gcc compiler that comes with your Linux distribution.

How to setup the disk-benchmark in your Linux system:
Installation of the disk-benchmark is as simple as this:

# git clone https://github.com/illumine/disk-benchmark
# cd disk-benchmark/src/
# gcc disk-benchmark.c -o disk-benchmark  -l pthread -lrt  -O3  -Wall
# ls -l disk-benchmark
-rwxr-xr-x 1 root root 23365 Apr 15 10:23 disk-benchmark

A simple scenario implementation using disk-benchmark

Scenario: 10 concurrent users each writing and reading a file of size ~10MB in /var.  Each user pauses for some seconds randomly picked from the interval [2,10] sec.  The command that implements the above scenario has as follows:

[root@mo-8f752419d src]# ./disk-benchmark -p /var -t 10 -a 10000000 -E 2:10

Test scenario:
test path=/var
Threads=10, sleep sec between write/read = 1, repeats per thread=5, random pick sleep sec from [2 10]
Lower file size=1024, Upper file size=10240, Absolute file size=10000000
Read/Write buffer size=8192,  Buff Siz W 0, Buf Siz R 0,
Do write only=0, Delete files=1
Print values only=0 dont print scenario info= 0, dont print clocks=0 dont print headers=0 print date=1
Work Continously=0  Work Continously Sleep Brake=5

T=7, Avg W=0.016134 Avg R=0.002160 Total W=0.080671 Total R=0.010801 Total Time=0.091473 Sleep=4.600000  Avg File Size =10000000.000000
T=2, Avg W=0.014436 Avg R=0.002411 Total W=0.072179 Total R=0.012056 Total Time=0.084234 Sleep=4.800000  Avg File Size =10000000.000000
T=4, Avg W=0.016104 Avg R=0.002189 Total W=0.080520 Total R=0.010943 Total Time=0.091463 Sleep=4.800000  Avg File Size =10000000.000000
T=9, Avg W=0.011966 Avg R=0.002069 Total W=0.059829 Total R=0.010347 Total Time=0.070176 Sleep=4.800000  Avg File Size =10000000.000000
T=6, Avg W=0.013065 Avg R=0.001826 Total W=0.065323 Total R=0.009128 Total Time=0.074451 Sleep=5.000000  Avg File Size =10000000.000000
T=1, Avg W=0.015399 Avg R=0.003005 Total W=0.076996 Total R=0.015025 Total Time=0.092021 Sleep=5.200000  Avg File Size =10000000.000000
T=8, Avg W=0.012883 Avg R=0.002303 Total W=0.064416 Total R=0.011513 Total Time=0.075930 Sleep=5.200000  Avg File Size =10000000.000000
T=3, Avg W=0.015850 Avg R=0.002492 Total W=0.079251 Total R=0.012458 Total Time=0.091709 Sleep=5.400000  Avg File Size =10000000.000000
T=0, Avg W=0.013430 Avg R=0.002697 Total W=0.067151 Total R=0.013487 Total Time=0.080637 Sleep=5.600000  Avg File Size =10000000.000000
T=5, Avg W=0.016659 Avg R=0.002387 Total W=0.083293 Total R=0.011934 Total Time=0.095226 Sleep=5.600000  Avg File Size =10000000.000000

T=-1, Avg W=0.014593 Avg R=0.002354 Total W=0.072963 Total R=0.011769 Total Time=0.084732 Sleep=5.100000  Avg File Size =10000000.000000
Wall time 28.000000, CPU time 0.880000
Tue Sep 12 13:36:26 2017


Monday, 7 March 2016

Fedora 22 Apache Tomcat and Httpd. Publishing an application in minutes.

Recalling from the previous article "Quest of the Holy Cloud" I got a provider and started a simple VM over there.
One of my first actions was to baptize my server and give it a fancy hostname.
Now lets come to the juicy part. In this article I am going to build a simple application server to handle PDF trans-code to images with a custom Java application I built.
The actions I am going to demonstrate are how to:
  • Setup OpenJKD on Fedora 22
  • Install Ghostscript libraries required for my application.
  • Download, install and configure Apache Tomcat 7
  • Install and configure Apache HTTPd.
  • Installing Open JDK

Install OpenJDK

The first step is really easy. We need a JDK or a JRE in order to run Tomcat that hosts our application. The straight option is to use opensource community JAVA: OpenJDK.
To do so, I entered the following commands:
# dnf install java
Last metadata expiration check performed 1:09:31 ago on Mon Mar  7 12:20:26 2016.
...
To check where java is and what has been installed:
# which java
/bin/java
# java -version
openjdk version "1.8.0_72"
OpenJDK Runtime Environment (build 1.8.0_72-b15)
OpenJDK 64-Bit Server VM (build 25.72-b15, mixed mode)

Install Ghostscript

Most of the software I wrote rely to Ghostscript shared libraries that are called from the corresponding Java API. To install them I entered the following commands:
# dnf install ghostscript
Last metadata expiration check performed 1:15:36 ago on Mon Mar  7 12:20:26 2016.
..
The library got installed at:
# ls -lh /lib64/libgs*
..
-rwxr-xr-x. 1 root root 16M Mar 31  2015 /lib64/libgs.so.9.16

# file  /lib64/libgs.so.9.16
/lib64/libgs.so.9.16: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, BuildID[sha1]=6601d742a4829cb3e4fe8197f1b1457f665ce130, stripped

Install Apache Tomcat 7

Apache Tomcat 7 can be downloaded from here as a tar.gz file by picking up a binary distribution as follows:
# cd /opt
# wget http://mirror.serversupportforum.de/apache/tomcat/tomcat-7/v7.0.68/bin/apache-at-7.0.68.tar.gz
# tar -xvf apache-tomcat-7.0.68.tar.gz

Now tomcat is not provided as a service from Fedora. To do so, we need to create a simple start script in /etc/init.d:

# cd /etc/init.d
# vi tomcat
paste the following to the script tomcat:
#!/bin/bash
# start/ stop Tomcat script
# Since you are using OpneJDK put this as your java home
JAVA_HOME=/
export JAVA_HOME
PATH=$JAVA_HOME/bin:$PATH
export PATH
# Where you have placed tomcat
CATALINA_HOME=/opt/apache-tomcat-7.0.68

case $1 in
start)
sh $CATALINA_HOME/bin/startup.sh
;;
stop)
sh $CATALINA_HOME/bin/shutdown.sh
;;
restart)
sh $CATALINA_HOME/bin/shutdown.sh
sh $CATALINA_HOME/bin/startup.sh
;;
esac
exit 0
Now tomcat needs to be registered as a Linux service. To do so add those commands:
# cd /etc/init.d
# chmod 755 tomcat  
# chkconfig --add tomcat  
# chkconfig --level 234 tomcat on  
# chkconfig --list tomcat 

Installing Apache HTTPD

This comes as a standard service supported from Fedora distribution. To install it:
# dnf install httpd
...
For a very fast configuration of http you can edit httpd.conf and add a simple virtual host:
#  vi /etc/httpd/conf/httpd.conf
# add where "Listen 80" is:
Listen My.Host.IP.Here:80

    DocumentRoot "/www/illumineit.com"
    ServerName www.illumineit.com

    # Other directives here

Since in modern Cloud environments the linux firewall IP Tables may block everything, here are the commands to unlock the ports:
iptables -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
iptables -A INPUT -p tcp -m tcp --dport 443 -j ACCEPT
You can start the HTTP service and get its status:

# service httpd start
Redirecting to /bin/systemctl start  httpd.service
# service httpd status
Redirecting to /bin/systemctl status  httpd.service
 httpd.service - The Apache HTTP Server
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; disabled; vendor preset: disabled)
   Active: active (running) since Mon 2016-03-07 14:09:27 UTC; 4s ago
 Main PID: 1760 (httpd)
   Status: "Processing requests..."
   CGroup: /system.slice/httpd.service
           ├─1760 /usr/sbin/httpd -DFOREGROUND
           ├─1761 /usr/sbin/httpd -DFOREGROUND
           ├─1762 /usr/sbin/httpd -DFOREGROUND
           ├─1763 /usr/sbin/httpd -DFOREGROUND
           ├─1764 /usr/sbin/httpd -DFOREGROUND
           └─1765 /usr/sbin/httpd -DFOREGROUND

Mar 07 14:09:27 securepdf.illumineit.com systemd[1]: Starting The Apache HTTP Server...
Mar 07 14:09:27 securepdf.illumineit.com systemd[1]: Started The Apache HTTP Server.
The deployment directory for tomcat where you can place your WAR files is: /opt/apache-tomcat-7.0.68/webapps/ since I have donwloaded and installed tomcat on /opt.
You can use WinSCP to copy your WAR file there:

# ls -lh  /opt/apache-tomcat-7.0.68/webapps/
total 27M
drwxr-xr-x. 14 root root 4.0K Mar  3 11:00 docs
drwxr-xr-x.  7 root root 4.0K Mar  3 11:00 examples
drwxr-xr-x.  5 root root 4.0K Mar  3 11:00 host-manager
drwxr-xr-x.  5 root root 4.0K Mar  3 11:00 manager
drwxr-xr-x.  3 root root 4.0K Mar  3 11:00 ROOT
drwxr-xr-x.  4 root root 4.0K Mar  4 16:59 zsecure-pdf
-rw-r--r--.  1 root root  27M Mar  4 16:59 zsecure-pdf.war

Friday, 4 March 2016

Set you linux host name and domain

Recently I have created a new VM linux server on CloudSigma. The Server runs Fedora 22. In order to setup the hostname and network domain I have changed the following files:

[root@illumine ~]# cat  /etc/host
securepdf

[root@illumine ~]# cat /etc/hostname
securepdf

[root@illumine ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

178.XXX.XXX.132   securepdf.illumineit.com securepdf

Test it using ping:

[root@securepdf ~]# ping securepdf
PING securepdf.illumineit.com (178.XXX.XXX.132) 56(84) bytes of data.
64 bytes from securepdf.illumineit.com (178.XXX.XXX.132): icmp_seq=1 ttl=64 time=0.036 ms



Tuesday, 5 November 2013

My Linux Shell Cook-Book

How many times we struggle ourselves to remember how to write correctly a for loop in shell ?
When was the last time we did a search for string comparison in bash and test for a file timestamp?

My favourite treatment for weak memory or "shell syntax blackouts" is a simple text file called
MyBashCooks.txt which takes proudly always the first tab in Notepad++ when I am coding scripts.

I think it is void to mention that this small file is hand on the web and travels with me when I am visiting clients, generally, it is one of the very few things I have handy and don't move a second step without it.

The recipes in my cookbook share a common secret: single command line, so you can use them on the command prompt as is or break them in several lines inside your scripts.

I think we say too much on this, please enjoy and if you find a mistake, please drop me a line:

# If then else in a single line
r=ee; if [ "$r" == "" ] ;  then  echo "is null" ; else  echo "not null"; fi

# If then else ARITHMETIC Operations
x=0;if [ $x -eq 0 ]; then echo "x=0";else echo "other"; fi

# Check if word belongs to string and if it does, run a shell command 
# Compatible with all shells
string="this is a string "; word="str";test "${string#*$word}" != "$string" && echo "$word found in $string"

# Negative of the previous
string="this is a string "; word="xxx";test "${string#*$word}" != "$string" || echo "$word not found in $string"

# Combined case of found and not found....
string="this is a string "; word="xxx";test "${string#*$word}" != "$string" && echo "Executes when found." || echo "Executes when NOT found."


# single line while loop
while true; do  echo '----'; sleep 1 ; done

while true; do top -b -n 1  |  egrep  'top|Tasks|Cpu|Mem|Swap|PID|mysql' | grep -v root   ;sleep 10; echo '----' ; done

# single line for loop
for h in {app0,app1,app2,app3,index0,index1,index2,index3};  do echo $h; sleep 1;  done

# Tests the existence  of word in a string: works in all POSIX shells (bash, dash, korn...) 
string="my name is MyBighrase";word="e i"; echo "search [$word] in [$string]";test "${string#*$word}" != "$string" && echo "$word found in $string"

# From UNIX timestamp to date:
echo 1365436826 | gawk '{print strftime("%c", $0)}'

# From Date to timestamp:
date --date='04/04/2013 20:30:01' +"%s"

# Format Date output
date +"%m-%d-%y"

# Search for a string across directories with grep
find -RH theString /this/directory

# Serach for line numbers and cut a file only from line to line:
this one searches for all line numbers with date 20130607
cat  slow.log | grep -n 130607  
we get the lines of this date exists and isolate those numbers in a new file.
cat  slow.log | sed -n '16582739,17369638p' > slow_20130607.txt

# Monitoring Linux Processes

while true ; do top -b -n 1 -p 2163 >> mysql_3000.txt ; sleep 15 ;  done &

while true ; do date >> tmpfs_3000.txt ; df -h | grep mysql ; sleep 15 ;  done >> tmpfs_3000.txt &

while true ; do date >> process_3000.txt;  echo "show full processlist;" |  mysql -uroot -pmypass | grep -v Sleep >> process_3000.txt  ; sleep 15 ; done &